Percent Proportions

Front

What is a percent proportion?

Back

A percent proportion is a way to express a part of a whole as a percentage. It is often used to compare a part to the total amount.

Front

How do you calculate the percentage of a quantity?

Back

To calculate the percentage of a quantity, divide the part by the whole and then multiply by 100. Formula: (Part/Whole) x 100.

Front

If 30% of a collection is a certain number, how do you find the total collection size?

Back

To find the total collection size, divide the number of items that represent 30% by 0.30. Formula: Total = Part / (Percentage/100).

Front

In Russell's collection of 1,000 pennies, how many are dated before 1980 if 30% are dated before 1980?

Back

300 pennies are dated before 1980 (30% of 1000 = 0.30 x 1000 = 300).

Front

If 40% of Russell's pennies are dated from 1980 to 2000, how many pennies does that represent?

Back

400 pennies are dated from 1980 to 2000 (40% of 1000 = 0.40 x 1000 = 400).

Front

How do you find the remaining percentage of a collection?

Back

To find the remaining percentage, subtract the sum of known percentages from 100%. For example, if 30% and 40% are known, the remaining percentage is 100% - (30% + 40%) = 30%.

Front

How many pennies in Russell's collection are dated after 2000 if 30% are before 1980 and 40% are from 1980 to 2000?

Back

300 pennies are dated after 2000 (1000 - (300 + 400) = 300).

Front

What is the formula to convert a fraction to a percentage?

Back

To convert a fraction to a percentage, divide the numerator by the denominator and multiply by 100. Formula: (Numerator/Denominator) x 100.

Front

If a student scores 75% on a test with 20 questions, how many questions did they answer correctly?

Back

The student answered 15 questions correctly (75% of 20 = 0.75 x 20 = 15).

Front

What does it mean if a value is increased by 20%?

Back

Increasing a value by 20% means adding 20% of that value to itself. For example, if the original value is 100, the new value is 100 + (0.20 x 100) = 120.